I knew what was happening. The adrenaline was kicking in, and the fight-or-flight response was draining the fine motor control from my fingers. I was powerless to stop it. I also knew it didn't sound too good, so later I felt this sense of failure. Even a desire to quit and not try it ever again.
Then I realized that was just my fixed mindset talking--the belief that abilities are fixed. The fixed mindset makes us want to avoid situations in which we might fail, because that would mean we're no good. It's especially powerful when we believe we are good at something, because then that belief is threatened by failure. It's what's behind the common belief that effort is bad, because it means you're not naturally smart or talented enough. It believes that success should be instant. And breeds a fear of failure.
The growth mindset, on the other hand, is the belief that success always requires effort, failure is a necessary part of the process, and growth is always possible.
While I have a growth mindset in some areas, I have fixed mindset in others, like my singing. I guess maybe it's because I grew up being told how good I was at singing, and so it became a part of my identity, and I guess failure threatens that.
But it's time to approach musical performance like any other challenge: failure is just the by-product of pushing the envelope.
So bring it on. I'll keep working on the self-accompaniment as long as there are folks patient enough to put up with my failures.
Come to think of it, that's a big part of my role as a teacher--to put up with my students failures, and not just to put up with them, but encourage them, because failures are necessary stepping stones to success.